This invention relates in general to container closure caps and in particular to such styles of caps which include tamper-proof or tamper-indicating features.
During the marketing of various industrial and consumer items, the container in which materials, primarily fluids and liquids, are shipped may be subject to being opened and tampered with during shipment and such tampering may go unnoticed. With perishable materials this may result in spoiled contents at the retail outlet. With chemicals, contamination may result in making the chemicals unuseable. In order to minimize such tampering or at the very least to provide an indication of whether or not such tampering was attempted, a number of container styles have incorporated therewith tamper-proof means or tamper-indicating means. Such tamper-related means are intended to clearly indicate whether or not any individual gained access to the contents of the particular container.
One very common example of such a tamper proof-closure concept is found on plastic containers of milk. Another similar type of device can be found on cola and soft-drink containers which incorporate a metal cap and perforated therewith a retaining ring. In the event the interface between the cap and retaining ring is broken, it becomes very evident that one may have gained access to the container and consequently the consumer is forewarned of a potential problem. Such cap and closure concepts are not limited solely to the food industry but have similar applicability to the chemical processing industry and other similarly related areas where materials are shipped in containers.
Although such tamper-proof closure concepts are often molded, a variety of manufacturing techniques are available, yet regardless of the material or manufacturing process employed, the aspects of part cost, complexity and user acceptance remain relevant. If the design of the tamper-proof closure cap is such that it necessitates a relatively complex mold and a resultant complex part, the cost alone may force potential users to switch to another design. Another factor involves the nature of the container and cap, their reusability and the physical appearance of the container once the tamper-proof closure is defeated by the user.
The following listed patents each relate to closure cap concepts for containers wherein some type of tamper-proof indicating means is provided.
______________________________________ Patent No. Patentee ______________________________________ 2,162,712 Hamberger 2,162,754 Schauer 2,172,159 Conner et al. 3,352,448 Livingstone 3,441,161 Van Baarn 3,493,140 MacNeill 3,650,428 Miller 3,812,994 Feldman ______________________________________
Hamberger discloses a container and closure combination wherein the container outlet opening is provided with a plurality of lugs and the cap includes a lower removable skirt portion arranged to interlock with the lugs.
Schauer discloses a tamper-proof closure cap and container combination very similar to Hamberger with the exception that in one embodiment, the skirt portion which interlocks beneath the lugs is a separate component part from the resealable cap.
Conner et al. discloses container closure means of the type having a readily breakable portion which is necessarily broken when the closure means or one member thereof is removed to permit access through or discharge contents from the container. Although the cap itself has a removable lower skirt portion, there is also included a metal breaking device which must be first put into place on the mouth of the bottle.
Livingstone discloses a resilient closure concept which is designed to be attached by mere pressure to the flaring annular wall which surrounds an opening in a container.
Van Baarn discloses a bottle cap concept which includes an upper and lower pair of body sections hinged together and initially joined by a rupturable security seal. The bottle cap further includes a hand grip in a protective position relative to the rupturable security seal.
MacNeill discloses a tamper-proof closure arrangement for a container and related cap and includes a locking ring interposed therebetween and adapted to break apart when the cap is first loosened after it has been initially applied to the container.
Miller discloses a tamper-proof closure device for application to external threaded convolusions of a container. Ratchet teeth provided along the inner surface of a locking ring are adapted to interlock with complementary external teeth or protuberances on the container.
Feldman discloses a closure cap for the neck of a bottle or other container and includes a cap body having internal thread means designed to engage external threads on the neck and a ratchet ring connected to the body by means of a shoulder.
While each of these various devices represent a somewhat similar arrangement by their use of a removable skirt portion and some type of interlocking surface contour, such as ratchet teeth, these various designs still present certain disadvantages. For those designs which include a full circumference for the removable skirt portion or ring, the cost of the cap is greater due to additional material and mold complexity than would be the case with only a partial skirt portion or ring. With those designs which incorporate lugs or ratchet teeth as part of the raised container opening, the cost of the container due to the increased complexity is greater than if a conventional raised opening is utilized. A further disadvantage with many of the designs of the listed patents involves the opportunity to pry up on the ring or skirt portion or in some way warp its contour so as to allow certain edges to be separated from their interlocking members. Still other cap designs disclosed by these various patents are a disadvantage because they incorporate two separate component pieces to accomplish what can be achieved by a single component piece. The effects of this are realized by the inventory ordering and storing of parts. Those designs which include a retaining ring which separates from the resealable cap portion are not able to be reused by merely adding a new cap. The machine requirements to install a new retaining ring preclude the user in the field from being able to reseal the container in a tamper-proof manner for further shipment or storage.
A consideration of these various disadvantages by the applicant has resulted in the present invention which incorporates only a partial interlocking ring which fits beneath an interlocking tab remote from the container opening such that the ring cannot be pryed upwardly on and the container opening is a standard externally threaded opening. By using a standard threaded opening, containers can be mass-produced without the remote interlocking tab. If a tamper-proof arrangement is desired, this interlocking tab can be added later. These and other related improvements and advantages will be apparent from the descriptions which follow.